The present invention relates to transparent, fire-resistant glazing composed of at least two panes, a layer of a UV-curable material being arranged in each case between these panes, the processes for production thereof and to the use thereof as multiple glazing, in mobile units, for example doors and windows, or fixed as an element of walls or facades.
Fire-resistant glazing serves, for example, as a fire-resistant barrier in an opening in a wall or else in an otherwise non-transparent filling of a door leaf. Fire-resistant glazing must be configured such that it can withstand the action of fire and heat, according to the standard, for a predetermined period, for example 30, 60, 90 or 120 or even 180 min. More particularly, it must not allow flames to strike through and must, under some circumstances, as an additional requirement, provide a room with a reliable barrier against smoke. In addition, in particular applications, it must offer good insulation against heat and restrict the radiant heat of a fire source. Requirement criteria on fire-resistant glazing are regulated especially in European standards EN 1363-1 “Fire Resistance Tests, General Standards” and DIN EN 1634 part 1 “Fire Resistance Tests for Doors and Shutter Assemblies, Part 1 Fire Doors”.
In addition, fire-resistant glazing should also meet further requirements, for example, security requirements, especially requirements on impact resistance. In addition, fire-resistant glazing should also be suitable for sound insulation.
Commercially available laminated safety glass consists of at least two glass panes between which PVB (polyvinyl butyrate) films are generally arranged. The fragment-binding effect of the film is needed to ensure the safety glass properties. However, when such glasses are heated, the PVB film decomposes and forms inflammable gases which lead to flame formation on the side facing away from the fire and hence enable the spread of a fire.
A further commercially available fire-resistant safety glass consists of at least one heat-resistant, low-expansion glass ceramic pane or a thermally tempered borosilicate glass between which a fluorine-containing layer has been arranged.
In this case, sufficient adhesion between the glass or glass ceramic pane and the fluorine-containing intermediate layer is promoted using an adhesion promoter consisting of a fluorohydrocarbon and a solvent.
In addition, the bonding of glass ceramic or glass pane to films requires a complex and costly lamination operation, and a preliminary composite using elevated pressure and elevated temperatures, and also a subsequent autoclave operation.
When the glass ceramic pane is produced by means of a rolling process, a consequence is relatively high corrugation of the glass ceramic pane. A fluorine-containing film with a thickness of 0.5 μm is not very suitable in this case for production of a faultless end product which does not exhibit any bubbles in the laminated glass, since this film can only inadequately compensate for the unevenness in the glass ceramic pane. In order, however, to ensure such compensation, a costly and time-consuming grinding and polishing process of the glass ceramic pane is needed in addition.
Due to the only low layer thickness of the films used and the low elasticity thereof, the sound-insulating properties of laminated safety glasses with such films are also inadequate.
It is likewise not directly possible in the case of use of films to produce laminates from individual glass panes with a thickness of <4 μm, which meet the safety glass properties required according to the highest category of DIN EN 12600.